Grillo, founder of a movement that will rival even the biggest parties at elections next month, hopes to wipe out the old guard: "We will bring some exorcists to parliament," he said in an interview after a rain-drenched rally south of Rome.

The 64-year-old Grillo is quick with wisecracks but the his 5-Star Movement is no joke. It is currently Italy's second- or third-biggest party, depending on the poll, riding a wave of discontent at conventional politics and economic austerity.

Crossing Italy on his "Tsunami tour", Grillo hopes to overturn Italian politics in a way that has not happened since the "Clean Hands" corruption scandals buried a political generation in the early 1990s, making way for Berlusconi's political rise.

"Grillo is attracting people who are disgusted with politics," said Maurizio Pessato, of pollsters SWG.

Rivals decry the movement as a populist vehicle with vague policy aims and it lost some momentum towards the end of last year as criticism grew that Grillo's authoritarian style was stifling independent voices.

But the 5-Star Movement is still second only to Pier Luigi Bersani's Democratic Party (PD) at 17.2 percent, up almost 2 percentage points in two weeks, an SWG poll published on Friday said, tying Berlusconi's People of Freedom (PDL), which lost half a percentage point from a week earlier.

That means that more than 50 - Grillo says 100 - of the movement's candidates will fill parliament's 945 seats. None of the 5-Star candidates has ever been there, and most are complete newcomers to politics at any level.

His influence has already guaranteed Italy a new generation of lawmakers - more than half of those elected on February 24-25 will be novices, according to a study published last week.

NOVICES

Instead of the movement's leaders picking its candidates, the 5-Star Movement held a primary, a move the PD copied. Monti picked political novices for his list and Berlusconi's PDL eliminated candidates accused of ties to the mafia.

"A mother of three, a 23-year-old college graduate and an engineer," Grillo said, describing who he voted for in the primary. "Those are the people I want to see in parliament."

A calm, unimposing presence in the privacy of his camper-van, the opposite of the hyperactive, foul-mouthed persona he projects on stage, Grillo is not running for election himself, but is lending his "face and popularity to help others."

Grillo wants a referendum on whether Italy should stay in the euro and has policies ranging from free Internet access to scrapping a planned high speed rail link with France.

But his main appeal is his call to get rid of the political class that has led the country for two decades.

"The PDL says it will not put forward any candidates who are under criminal investigation... There won't be anyone left," Grillo growled from stage in a routine that targeted the politicians he hopes to sweep away.

Corruption and a recession helped turn 5-Star from a fringe movement into a real political force last year. In regional elections in October, it received more than 20 percent of the national vote and became the single-largest party in Sicily.

Thirty-six percent of Italian voters see the movement as the most transparent force in the election, by far the biggest percentage, a separate SWG poll showed on Friday.

The 5-Star Movement's candidates have an average age of 42, the lowest of any party. On Grillo's insistence, none has a criminal record or is under criminal investigation, and all have agreed to serve a maximum of two terms.

During the rally in Pomezia, the candidates stood timidly on stage behind Grillo as he ranted through his campaign routine.

To those concerned about the inexperience of the movement's candidates, Grillo pointed to the unknowns standing behind him: "I'd rather take a shot in the dark with these guys than commit assisted suicide with those others."